Basically, oxygen problems with the T-45 Goshawk (sounds much like the issues with with the F/A-18 as well), has lead to a situation where instructor pilots have refused to fly the T-45, leading to a cancellation of 40% of sorties. There has been a number of hypoxia related incidents reported with the T-45, including one last week where a student pilot had to be pulled out of his aircraft unconscious after being affected. This has resulted in the USN suspending flight operations with the T-45 temporarily to try to find a solution.

Almost all OBOGS-equipped aircraft have backup LOX, and the T-45 is no exception.

CheersA

Yes. The trick is recognising the symptoms of hypoxia and activiating the backup LOX. In the Hornet the backup LOX is held at the base of the seat and activiated by pulling a tab. IIRC it lasts about 10 minutes, enough time to drop altitude to breathable ranges.

The USS George H. W. Bush and the USS Carl Vinson both deployed in January specially equipped with hyperbaric chambers, devices that measure cockpit air pressure, and even issued commerically-bought Garmin wristwatches to air crew that have altimeters and barometric sensors built into them. Even then, it has been reported that there has been at least two instances onboard the Bush where the hyperbaric chambers were used by aircrew having hypoxia symptoms; once in Feb where a Growler crew had an abnormality with the aircraft's environmental control system and managed a landing back onboard, and the second instance happened in April when a solo F/A-18 pilot became disoriented shortly after takeoff. Both instances fortunately occurred close to the carrier, allowing pilots to quickly conduct a landing and seek immediate treatment.

While it appears that the Oxygen generators were fine, particularly as the same system is used on other aircraft with no problems, the T-45s didn’t have anything installed to scrub excess moisture from the air going into the OBOGS. The USN is testing a moisture separator to remove the moisture from the air, and are checking the air cooling system, introducing new maintenance procedures, and installing sensors to monitor air quality.